ISO/TS 20684-3:2022

TECHNICAL ISO/TS
SPECIFICATION 20684-3
First edition
2022-09
Intelligent transport systems —
Roadside modules SNMP data
interface —
Part 3:
Triggers
Systèmes de transport intelligents — Interface de données SNMP pour
les modules en bord de route —
Partie 3: Déclencheurs
Reference number
© ISO 2022
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Conformance . 2
5 User needs . 4
5.1 Schedule triggers . 4
5.1.1 Schedule triggers user need . 4
5.1.2 Schedule triggers design overview . 5
5.1.3 Schedule triggers graphical relationships . 5
5.2 Schedule day plans . 6
5.2.1 Schedule day plans user need . 6
5.2.2 Schedule day plans design overview . 6
5.2.3 Schedule day plans graphical relationships . 6
5.3 Condition-based triggers . 7
5.3.1 Condition-based triggers user need . 7
5.3.2 Condition-based triggers design overview . 8
5.3.3 Graphical relationships. 8
6 Requirements . 9
6.1 Action manager . 9
6.1.1 Action manager definition . 9
6.1.2 Action manager data exchange requirements . 9
6.1.3 Action manager capability requirements . 9
6.2 Conditional trigger . 9
6.2.1 Conditional trigger definition . 9
6.2.2 Conditional trigger data exchange requirements . 10
6.2.3 Capability requirements . 10
6.3 Day plan . 13
6.3.1 Day plan definition . 13
6.3.2 Day plan data exchange requirements .13
6.3.3 Day plan capabilities .13
6.4 Day plan scheduler . 14
6.4.1 Day plan scheduler definition . 14
6.4.2 Day plan scheduler data exchange requirements . 14
6.4.3 Day plan scheduler capabilities . 14
6.5 Trigger schedule .15
6.5.1 Trigger schedule definition . 15
6.5.2 Trigger schedule data exchange requirements . 15
6.5.3 Trigger schedule capabilities . 15
7 Security vulnerabilities .15
Annex A (normative) Management information base (MIB) .17
Annex B (normative) Requirements traceability matrix (RTM) .51
Bibliography .58
iii
Foreword
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
A list of all parts in the ISO 20684 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
Introduction
0.1  Background
The need for standardized communication with ITS field devices is growing around the world.
Several countries have adopted Simple Network Management Protocol (SNMP) based field device
communication standards.
There is a growing view and empirical evidence that standardizing this activity will result in improved
ITS performance, reduced cost, reduced deployment time, and improved maintainability. The ISO 20684
series extends ISO 15784-2 by defining the management information necessary to monitor, configure
and control features of field devices. The data elements defined in all parts of ISO 20684 series may be
used with any protocol but were designed with an expectation that they would be used with one of the
ISO 15784-2 protocols.
By using this approach, agencies can specify open procurements and systems can be expanded
geographically in an open and non-proprietary manner, which reduces costs, speeds up deployment,
and simplifies integration.
0.2  Overview
SNMP is a collection of well-thought-out and well-proven concepts and principles. SNMP employs the
sound principles of abstraction and standardization. This has led to SNMP being widely accepted as the
prime choice for communication between management systems and devices on the internet and other
communications networks.
The original implementation of SNMP was used to manage network devices such as routers and
switches. Since then, the use of SNMP has grown into many areas of application on the internet and has
also been used successfully over various serial communications networks.
This document defines management information for ITS field devices following the SNMP conventions.

0.3  Document approach and layout
This document defines:
a) the conformance requirements for this document (Clause 4);
b) a set of user needs for user-defined trigger conditions that can “fire” to initiate actions (Clause 5);
c) a set of detailed requirements for the identified user needs (Clause 6);
d) security considerations for the information defined in this document (Clause 7);
e) the management information bases that define the data for the defined requirements (Annex A);
f) the requirements traceability matrix (RTM) that traces the requirements to the design elements
(Annex B).
v
TECHNICAL SPECIFICATION ISO/TS 20684-3:2022(E)
Intelligent transport systems — Roadside modules SNMP
data interface —
Part 3:
Triggers
1 Scope
Field devices are a key component in intelligent transport systems (ITS). Field devices include traffic
signals, message signs, weather stations, traffic sensors, roadside equipment for connected ITS (C-ITS)
environments, etc.
Field devices often need to exchange information with other external entities (managers). Field devices
can be quite complex, necessitating the standardization of many data concepts for exchange. As such,
the ISO 20684 series is divided several individual parts.
This document specifies the needs, requirements and design for multiple mechanisms to fire triggers,
which result in the device attempting to perform an action. Specific types of actions are defined in
other documents and can include sending notifications (ISO/TS 20684-4), entering data into a log for
later retrieval (ISO/TS 20684
...